Hillman Round Head Combination Machine Screw is a fastening screw with a machine-cut thread throughout the length of its shank. These combination head screws are used with nuts or screwed directly into a threaded receptacle to fasten various components together in machines, tools, etc. Fasten the round head screw with a screwdriver to reduce risk of over-tightening and protect the screw and fastened material. Measured from underside of the head to tip of the screw to obtain fastener length If nuts are needed, use with nuts of same finish and threading Round head screw measures #10-24 diameter x 1" length Use combination head screws to fasten metal parts together Machine screw has zinc finish for moderate corrosion protection Fasten with screwdriver to reduce risk of over-tightening Stronger thread than wood screws, made finer and more precisely